/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
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 * CDDL HEADER END
 *
 *
 *      Copyright 2009 Sun Microsystems, Inc.
 */

package org.forgerock.opendj.ldap.schema;

import static org.forgerock.opendj.ldap.CoreMessages.ERR_ATTR_SYNTAX_MRUSE_UNKNOWN_ATTR1;
import static org.forgerock.opendj.ldap.CoreMessages.ERR_ATTR_SYNTAX_MRUSE_UNKNOWN_MATCHING_RULE1;

import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.forgerock.i18n.LocalizableMessage;

import com.forgerock.opendj.util.Validator;

/**
 * This class defines a data structure for storing and interacting with a
 * matching rule use definition, which may be used to restrict the set of
 * attribute types that may be used for a given matching rule.
 */
public final class MatchingRuleUse extends SchemaElement {
    // The OID of the matching rule associated with this matching rule
    // use definition.
    private final String oid;

    // The set of user defined names for this definition.
    private final List<String> names;

    // Indicates whether this definition is declared "obsolete".
    private final boolean isObsolete;

    // The set of attribute types with which this matching rule use is
    // associated.
    private final Set<String> attributeOIDs;

    // The definition string used to create this objectclass.
    private final String definition;

    private MatchingRule matchingRule;
    private Set<AttributeType> attributes = Collections.emptySet();

    MatchingRuleUse(final String oid, final List<String> names, final String description,
            final boolean obsolete, final Set<String> attributeOIDs,
            final Map<String, List<String>> extraProperties, final String definition) {
        super(description, extraProperties);

        Validator.ensureNotNull(oid, names, attributeOIDs);
        this.oid = oid;
        this.names = names;
        this.isObsolete = obsolete;
        this.attributeOIDs = attributeOIDs;

        if (definition != null) {
            this.definition = definition;
        } else {
            this.definition = buildDefinition();
        }
    }

    /**
     * Returns {@code true} if the provided object is a matching rule use having
     * the same numeric OID as this matching rule use.
     *
     * @param o
     *            The object to be compared.
     * @return {@code true} if the provided object is a matching rule use having
     *         the same numeric OID as this matching rule use.
     */
    @Override
    public boolean equals(final Object o) {
        if (this == o) {
            return true;
        } else if (o instanceof MatchingRuleUse) {
            final MatchingRuleUse other = (MatchingRuleUse) o;
            return oid.equals(other.oid);
        } else {
            return false;
        }
    }

    /**
     * Returns an unmodifiable set containing the attributes associated with
     * this matching rule use.
     *
     * @return An unmodifiable set containing the attributes associated with
     *         this matching rule use.
     */
    public Set<AttributeType> getAttributes() {
        return attributes;
    }

    /**
     * Returns the matching rule for this matching rule use.
     *
     * @return The matching rule for this matching rule use.
     */
    public MatchingRule getMatchingRule() {
        return matchingRule;
    }

    /**
     * Returns the matching rule OID for this schema definition.
     *
     * @return The OID for this schema definition.
     */
    public String getMatchingRuleOID() {
        return oid;
    }

    /**
     * Returns the name or matching rule OID for this schema definition. If it
     * has one or more names, then the primary name will be returned. If it does
     * not have any names, then the OID will be returned.
     *
     * @return The name or OID for this schema definition.
     */
    public String getNameOrOID() {
        if (names.isEmpty()) {
            return oid;
        }
        return names.get(0);
    }

    /**
     * Returns an unmodifiable list containing the user-defined names that may
     * be used to reference this schema definition.
     *
     * @return Returns an unmodifiable list containing the user-defined names
     *         that may be used to reference this schema definition.
     */
    public List<String> getNames() {
        return names;
    }

    /**
     * Indicates whether the provided attribute type is referenced by this
     * matching rule use.
     *
     * @param attributeType
     *            The attribute type for which to make the determination.
     * @return {@code true} if the provided attribute type is referenced by this
     *         matching rule use, or {@code false} if it is not.
     */
    public boolean hasAttribute(final AttributeType attributeType) {
        return attributes.contains(attributeType);
    }

    /**
     * Returns the hash code for this matching rule use. It will be calculated
     * as the hash code of the numeric OID.
     *
     * @return The hash code for this matching rule use.
     */
    @Override
    public int hashCode() {
        return oid.hashCode();
    }

    /**
     * Indicates whether this schema definition has the specified name.
     *
     * @param name
     *            The name for which to make the determination.
     * @return <code>true</code> if the specified name is assigned to this
     *         schema definition, or <code>false</code> if not.
     */
    public boolean hasName(final String name) {
        for (final String n : names) {
            if (n.equalsIgnoreCase(name)) {
                return true;
            }
        }
        return false;
    }

    /**
     * Indicates whether this schema definition has the specified name or
     * matching rule OID.
     *
     * @param value
     *            The value for which to make the determination.
     * @return <code>true</code> if the provided value matches the OID or one of
     *         the names assigned to this schema definition, or
     *         <code>false</code> if not.
     */
    public boolean hasNameOrOID(final String value) {
        return hasName(value) || oid.equals(value);
    }

    /**
     * Indicates whether this schema definition is declared "obsolete".
     *
     * @return <code>true</code> if this schema definition is declared
     *         "obsolete", or <code>false</code> if not.
     */
    public boolean isObsolete() {
        return isObsolete;
    }

    /**
     * Returns the string representation of this schema definition in the form
     * specified in RFC 2252.
     *
     * @return The string representation of this schema definition in the form
     *         specified in RFC 2252.
     */
    @Override
    public String toString() {
        return definition;
    }

    MatchingRuleUse duplicate() {
        return new MatchingRuleUse(oid, names, description, isObsolete, attributeOIDs,
                extraProperties, definition);
    }

    @Override
    void toStringContent(final StringBuilder buffer) {
        buffer.append(oid);

        if (!names.isEmpty()) {
            final Iterator<String> iterator = names.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" NAME ( '");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append("' '");
                    buffer.append(iterator.next());
                }

                buffer.append("' )");
            } else {
                buffer.append(" NAME '");
                buffer.append(firstName);
                buffer.append("'");
            }
        }

        if (description != null && description.length() > 0) {
            buffer.append(" DESC '");
            buffer.append(description);
            buffer.append("'");
        }

        if (isObsolete) {
            buffer.append(" OBSOLETE");
        }

        if (!attributeOIDs.isEmpty()) {
            final Iterator<String> iterator = attributeOIDs.iterator();

            final String firstName = iterator.next();
            if (iterator.hasNext()) {
                buffer.append(" APPLIES ( ");
                buffer.append(firstName);

                while (iterator.hasNext()) {
                    buffer.append(" $ ");
                    buffer.append(iterator.next());
                }

                buffer.append(" )");
            } else {
                buffer.append(" APPLIES ");
                buffer.append(firstName);
            }
        }
    }

    void validate(final Schema schema, final List<LocalizableMessage> warnings)
            throws SchemaException {
        try {
            matchingRule = schema.getMatchingRule(oid);
        } catch (final UnknownSchemaElementException e) {
            // This is bad because the matching rule use is associated with a
            // matching rule that we don't know anything about.
            final LocalizableMessage message =
                    ERR_ATTR_SYNTAX_MRUSE_UNKNOWN_MATCHING_RULE1.get(getNameOrOID(), oid);
            throw new SchemaException(message, e);
        }

        attributes = new HashSet<AttributeType>(attributeOIDs.size());
        AttributeType attributeType;
        for (final String attribute : attributeOIDs) {
            try {
                attributeType = schema.getAttributeType(attribute);
            } catch (final UnknownSchemaElementException e) {
                final LocalizableMessage message =
                        ERR_ATTR_SYNTAX_MRUSE_UNKNOWN_ATTR1.get(getNameOrOID(), attribute);
                throw new SchemaException(message, e);
            }
            attributes.add(attributeType);
        }
        attributes = Collections.unmodifiableSet(attributes);
    }
}